African crocodiles crossed the Atlantic log time ago. This is the discovery made by the University of Turin through the 3D reconstruction of the remains of the skull of a crocodile, found in Libya and preserved for almost a century at the University Natural Museum of Sapienza University in Rome.
According to the study of the Turin paleontologist Massimo Delfino, published in the Scientific Reports magazine, 7 million years ago some crocodile specimens would have left North Africa and probably crossed the Atlantic Ocean to arrive on the coasts of South America, where they have adapted and diversified giving rise to the Crocodylus species that still inhabit the American continent.
The work made it possible to reconstruct in 3D the only survivor of the five fossil skulls found in the early 1930s during a scientific expedition to Libya, in a location in northern Sahara called As Sahabi. The fossil studied has been preserved in the collections of the Roman museum for almost a century.
Experts said: “The specimen of Crocodylus checchiai is the best preserved skull of this species lived in the Miocene, over 7 million years ago, in Africa, when the Sahara was a territory very different from what it appears today, populated by large mammals and rich in vegetation and waterways.
We have seen that the As Sahabi crocodile shares with the American species numerous anatomical peculiarities . But not only that, we have compared, thanks to specific software, the data obtained with the anatomical characteristics of other existing and fossil species with the aim of carrying out a phylogenetic analysis which has clarified that this species represents a sort of link between African and American species."
Through the use of tomographic scans, the researchers obtained 3D images of both the inside and outside of the skull. The size of the head made it possible to establish that the crocodile was an adult and just over 3 meters long.
Lorenzo Rook, from Florence University said: "Ours is a result of extreme importance which enhances the historical collections of a unique paleontological deposit for understanding the fauna of the circum-Mediterranean area at the end of the Miocene."
The results of the study are also confirmed from a chronological point of view. In fact, in the New World, the oldest fossils of Crocodylus date back to the beginning of the Pliocene (5 million years ago), resulting much more recent than the species studied.
It is therefore possible that during the Miocene some specimens of "checchiai" (or a similar and still unknown form) crossed the Atlantic Ocean arriving on the coasts of South America. The results of this study represent an important contribution to reconstruct the evolutionary history and paleobiogeography of crocodiles, that is, the methods and times with which these reptiles colonized the different continents reaching their current geographical distribution.
The research, developed together with the director of the University Museum of Earth Sciences, Raffaele Sardella, and with the collaboration of the University of Florence, places the African find of the Miocene, identified as Crocodylus checchiai, at the base of the evolutionary tree of American crocodiles.